diff --git a/src/main/java/org/gcube/portlets/user/notifications/client/view/NotificationsPanel.java b/src/main/java/org/gcube/portlets/user/notifications/client/view/NotificationsPanel.java
index 0e6bbaf..7b1f84f 100644
--- a/src/main/java/org/gcube/portlets/user/notifications/client/view/NotificationsPanel.java
+++ b/src/main/java/org/gcube/portlets/user/notifications/client/view/NotificationsPanel.java
@@ -54,6 +54,8 @@ public class NotificationsPanel extends Composite {
 	private ShowMoreNotifications showMoreWidget;
 	//needed to know the next range start
 	private int fromStartingPoint = 0;
+	//needed to avoid to call the doShowMoreNotifications when the forst call has not returned yet
+	private boolean lockNotificationUpdate = false;
 
 	private VerticalPanel container = new VerticalPanel();
 	private HorizontalPanel settingsPanel = new HorizontalPanel();
@@ -120,8 +122,9 @@ public class NotificationsPanel extends Composite {
 			@Override
 			public void onWindowScroll(ScrollEvent event) {
 				boolean isInView = isScrolledIntoView(showMoreWidget);
-				if (isInView) {
+				if (isInView && !lockNotificationUpdate) {
 					doShowMoreNotifications();
+					lockNotificationUpdate = true;
 				}
 			}
 		});
@@ -189,13 +192,14 @@ public class NotificationsPanel extends Composite {
 	/**
 	 * called when a user scroll down the page to the bottom	
 	 */
-	private void doShowMoreNotifications() {	
+	private void doShowMoreNotifications() {
+		GWT.log("doShowMoreNotifications()");
 		showMoreNotificationsPanel.remove(0);
 		loadingImage.getElement().getStyle().setMargin(10, Unit.PX);
 		showMoreNotificationsPanel.add(loadingImage);
 		int from = (fromStartingPoint == 0) ? NotificationConstants.NOTIFICATION_NUMBER+1 : fromStartingPoint;
 		fromStartingPoint = from;
-		final int quantity = 20;
+		final int quantity = 10;
 		GWT.log("StartingPoint = " + from);
 
 		notificationService.getUserNotificationsByRange(from, quantity, new AsyncCallback<HashMap<Date,ArrayList<Notification>>>() {
@@ -220,9 +224,11 @@ public class NotificationsPanel extends Composite {
 						GWT.log("Show MORE ");
 						showMoreNotificationsPanel.setHorizontalAlignment(HasAlignment.ALIGN_CENTER);
 						showMoreWidget = new ShowMoreNotifications();
+						showMoreNotificationsPanel.clear();
 						showMoreNotificationsPanel.add(showMoreWidget);
 						mainPanel.add(showMoreNotificationsPanel);
 					}
+					lockNotificationUpdate = false;
 				}
 			}
 			@Override
diff --git a/src/main/webapp/Notifications.css b/src/main/webapp/Notifications.css
index d4fb6af..51fd301 100644
--- a/src/main/webapp/Notifications.css
+++ b/src/main/webapp/Notifications.css
@@ -54,7 +54,7 @@ a.link:hover {
 .new-notifications-show {
 	opacity: 1;
 	background: #D6E2FC;
-	height: 18px;
+	height: 38px;
 }